Question

Which of the following is nonpolar? (A) B

Answer 1

The electron/s is shared between the atom is equal in charge and magnitude then the molecule is Non-polar. Eg: F₂, Cl₂

The electron/s are shared between atoms are unequal in charge and magnitude then the molecule is Polar. Eg: NaCl, KCl.

To answer this question you should know the following concept:

1) Dipole moment= Charge x Distance between atoms.

  Dipole moment = 0, Non Polar

Dipole moment ≠ 0, Polar

2) To make it simple, An identical atom or lone pair of electrons are opposite to each other then the dipole moment of a molecule will be zero. That is Non-polar.

3) If a non-identical atom or lone pair of electrons are opposite to each other then there will be a dipole moment. That is Polar.

4) suppose an identical atom or lone pair of electrons is not the exact opposite to each other then there will be a dipole moment. that is polar.

In the question. a) molecule is tetrahedral geometry so definitely no molecule will opposite to each other so there will be no dipole moment

b) & d) No atoms or lone pair of electrons are opposite to each other so there will be no dipole moment

If you note the molecule c) Each identical molecule or lone pair of electrons are opposite to each other. The dipole moment will be zero. then the molecule is Non-polar.

The answer is C)